1. Technical Field
Aspects of the present invention relate to a thrust reverser of a propulsion system nacelle, and more particularly relate to an aerodynamic feature for aft edge portions of a thrust reverser lower bifurcation wall.
2. Background Information
It is known to provide a propulsion system that includes an engine (e.g., a gas turbine engine), a nacelle that at least partially surrounds the engine, and a pylon that connects the engine and the nacelle to a vehicle (e.g., an aircraft). In some instances, the thrust reverser includes a fixed structure and a translating structure that at least partially define an annular bypass airstream duct. The fixed structure includes a radially outer fixed structure and a radially inner fixed structure. The outer fixed structure includes an annular cascade array. The inner fixed structure includes an annular wall having a wall outer surface and a wall inner surface. The wall outer surface partially defines the bypass airstream duct, and the wall inner surface partially defines a cavity through which a portion of the engine extends. The translating structure includes a translating sleeve and a plurality of blocker doors. The translating structure is moveable relative to the fixed structure, between a stowed position (e.g., during a forward thrust operation) and a deployed position (e.g., during a thrust reversing operation). When the translating structure is in its stowed position, a bypass airstream can pass from a forward end of the bypass duct to an aft end of the bypass duct and a nozzle, through which it can be discharged to provide forward thrust. In the stowed position, the translating sleeve prevents the bypass airstream from passing through the cascade array. When the translating structure is moved from its stowed position to its deployed position, the translating sleeve moves relative to the fixed structure and the blocker doors are drawn down into the bypass duct, thereby exposing the cascade array to the bypass airstream and the ambient air surrounding the thrust reverser. The blocker doors redirect a portion of the bypass airstream toward the cascade array, through which the bypass airstream can be discharged to generate reverse thrust.
In known thrust reverser designs, the inner fixed structure of the thrust reverser (like the thrust reverser as whole) is bifurcated into a left side section and a right side section. The left and right side sections of the inner fixed structure each include an upper bifurcation wall and a lower bifurcation wall. The annular wall extends between the respective upper and lower bifurcation walls of the left and right side sections of the inner fixed structure. The lower bifurcation walls each extend between a forward edge portion and an aft edge portion. The lower bifurcation walls of the left and right side sections are disposed relative to one another. The respective aft edge portions of the lower bifurcation walls typically have a blunt, non-aerodynamic shape that can cause aerodynamic drag due to flow separation. Aspects of the present invention are directed to this and other problems.